High pressure medicinal dispensers are utilized to inject either fluid or semi-fluid medicinal mixtures under high pressure to desired locations in precisely measured amounts and with only minimal manual force applied. Typically, the high pressure dispenser has a syringe barrel with a cylindrical body and a nozzle at one end, such as disclosed by U.S. Pat. No. 4,312,343. A threaded rod may be attached to a knob at one end and a piston at the other. The threaded rod and syringe barrel are commonly held together by a collar. In operation, the knob is utilized to manually rotate the threaded rod, moving the rod into the cylindrical body of the syringe barrel, which allows the piston, attached to one end of the threaded rod, to move the mixture within the cylindrical body of the syringe barrel through the nozzle and to a desired location. Additionally, some conventional designs have a handle interconnected with the syringe barrel.
However, the overall strength of the conventional devices may be limited by the manner in which the individual dispenser components are manufactured and interconnected. The limitations placed upon the strength of the overall conventional devices, as well as the individual high pressure dispenser components, limits the pressure at which the mixture can be injected and the pressure that the dispenser can physically withstand.
Moreover, conventional high pressure dispensers have poor ergonomic characteristics. For example, conventional handles are very small in diameter. Additionally, conventional knobs have relatively short axial lengths. Hence, the disadvantages exhibited by the conventional devices include limitations pertaining to the ability of an operator to maintain manual control of the high pressure dispenser, as well as manually rotate the threaded rod.
Additionally, conventional syringe barrels have sharp angles on the interior of the syringe barrel between the cylindrical interior surface of the syringe barrel and the nozzle. As a result of the sharp angles, the interior surface of the syringe barrel has a funnel or conical shaped transition from the cylindrical interior surface to the nozzle. However, such a design yields poor flow characteristics when used with viscous fluids at high pressure.
The present invention alleviates one of more of the shortcomings described above. 